1. Field of the Invention
The present invention is related to a transmission plug and related complex earphone and radio player, and more particularly, to a transmission plug and related complex earphone and radio player capable of increasing an utilization range.
2. Description of the Prior Art
Handheld radio players, such as satellite, digital, AM/FM (amplitude modulation and frequency modulation) broadcast receivers, can receive broadcast signals and send out radio programs after operations like demodulation and audio signal processing. In order to receive the broadcast signals and outputting audio signals, a handheld radio player equips two independent interfaces; one is utilized for coupling to an antenna for receiving the broadcast signals, and the other is for coupling to an earphone or a speaker to output the audio signals. Under such circumstance, since interfaces of the antenna and the earphone are independent, and the broadcast signals and the audio signals are transmitted via different lines, the handheld radio player easily causes a messy condition and decreases convenience. Therefore, the prior art has developed an integrated interface to improve the problems mentioned above.
Please refer to FIG. 1. FIG. 1 is a schematic diagram of a handheld radio player 10 of the prior art. The handheld radio player 10 comprises a radio receiver 100, a complex earphone 102, a transmission interface 104 and a complex transmission line 106. Except an audio output device 108, the complex earphone 102 further includes a reception antenna 110, which connects to the radio receiver 100 via the complex transmission line 106 and the transmission interface 104. The transmission interface 104 is an integrated interface which transmits the broadcast signals and the audio signals via different pins. The complex transmission line 106 is a combination of multiple lines utilized for transmitting the broadcast signals and the audio signals. Therefore, while the handheld radio player 10 is in operation, the broadcast signals received by the reception antenna 110 are transmitted to the radio receiver 100 via the complex transmission line 106 and the transmission interface 104. After operations of filtering, demodulation and audio signal processing, the radio receiver 100 transmits the audio signals to the audio output device 108 via the transmission interface 104 and the complex transmission line 106, to send out the radio programs.
In FIG. 1, the handheld radio player 10 transmits the broadcast signals and the audio signals merely via the single transmission interface 104 and the complex transmission line 106, so as to reduce the messy condition and enhance the convenience. However, a type of the transmission interface 104 is usually unique and set up by related manufacturers, which does not conform to an international standard. Hence, the earphone 102 only matches the radio receiver 100, causing a limited utilization range of the earphone 102.